This invention relates to a video guidance aid for assisting the operator to steer or guide a tractor towing a wide implement, such as a planter.
With conventional planter guidance systems, a marker on the end of a lengthy boom, which is attached to an end of the planter, creates a mark in the ground. The operator then steers the tractor on the next pass so as to straddle the mark made on the previous pass. This requires that the length of the boom be one-half the total width of the planter. This long boom adds undesirable weight to the planter. This boom must be retractably or pivotally mounted on the planter to provide clearance for the planter during transportation. To solve this problem, guidance aiding systems have been proposed in which a TV camera is rigidly mounted on an end of a planter so that an image of a mark, created in the soil during a previous pass of the planter, may be viewed by the tractor operator from a TV monitor mounted in the cab of the tractor. Such guidance aiding systems have suffered from the natural tendency of the vehicle operator to over-steer when relying on the image displayed on the TV monitor. Part of this over-steering problem was caused by time delays between steering changes of the tractor and the resulting pivoting or turning of the planter. Having the TV camera fixed, rather than pivotal, relative to the planter also contributed to the over-steering.